New Zealand earlier today used the permanent U.N. conference on disarmament to call for a Southern Hemisphere free of nuclear weapons. Matt Robson, disarmament and arms control minister, told the other 65 members of the conference a great deal of the political spadework would be needed to make his proposal a reality. New Zealand’s proposal would bring together signatories of existing Southern Hemisphere non-nuclear treaties to insist that the seas, too, should be closed to nuclear weapons transports. But the five official nuclear powers—Britain, China, France, Russia and the United States—are loathe to give up what they see as their right to transport nuclear weapons through international waters.